With each heartbeat, with each pulse of blood though an artery, with each breath taken and released, one counts the passing of time.

As the sun rolls over the sky, the shadow of the pointer moves the sundial, and flowers turn their faces to its warmth. Sand falls through an hourglass. A melting candle devours the lines scored in its wax. The pendulum swings, and all the little wheels and gears of the clock click-clack though another tiny compartment of time. The moon rises and sets, waxes and wanes, and the tides mark out their hours on the strand. Seasons change and wheel about again, and a child grows into a man and then declines towards death.

All these things can be felt, seen, measured.

Yet they are merely shadow pictures of time’s true being. Time is not the measure of the passing of seconds, seasons, centuries. It is not a river which flows smoothly and inexorably forward. It is the warp of the weave of the universe, and so hums at the very heart of all matter.